1. Field of the Invention
The present invention relates to a sublimation type color printer used for an output device for a digital photograph. This application is based on Japanese Patent Application No. Hei 11-273456, the contents of which are incorporated herein by reference.
2. Description of the Related Art
Recently, an output device which can prints a high-quality picture at low-cost is required due to the popularization of the digital camera. In response to this requirement, there is a sublimation type (heat transcription type) color printer which prints a picture on a paper pulled out from a roll of the paper. The adoption of the rolled paper is moreadvantageous than a pre-cut paper in terms of costs.
FIG. 6 shows a structure of a conventional sublimation type color printer. In this figure, reference number 1 denotes a paper, reference number 2 denotes a roll of the paper 1, reference number 3 denotes a platen, reference number 4 denotes a pair of first transfer rollers, reference number 5 denotes a pair of second transfer rollers, reference number 6 denotes a cutter, reference number 7 denotes a paper guide, reference number 8 denotes a thermal head, reference number 9 denotes an ink ribbon, and reference number 10 denotes a paper outlet.
In this sublimation type color printer, an operator sets the roll 2 at the predetermined position, and pulls the leading edge of the paper 1 from the roll 2 and manually inserts the tip between the first transfer rollers 4, in preparation for the operation. Next, the operator gives a paper induction command by operating a switch button (omitted in the Figure) for example, then, an initial operations such as cutting the leading edge of the paper 1 are done, and the tip is finally guided to a print stand-by position PS in FIG. 7. At this print stand-by position PS, the leading edge of the paper 1 projects slightly from the first transfer rollers 4 in the direction of the second transfer rollers 5.
Further, as a result of giving a print command at the print stand-by position PS shown in FIG. 7, a print operation is carried out and the paper 1 reciprocates within a predetermined printing area. In the normal color print, the printed colors are expressed by stacking the layers of three colors: yellow (Y), magenta (M), and cyan (C), on the paper 1, and an overcoat layer covers these layers for preventing the fading of the colors. Therefore, in the case of the conventional printer as shown in the Figure, the paper 1 reciprocates four times within the printing area, and the printing by the each ink ribbon which corresponds to the each color of Y, M, and C, and the coating of the overcoat layer are successively carried out.
The print operation for a piece of paper is finished in the above-described manner, and then, the paper 1 is cut by the cutter 6 to the predetermined length and ejected from the outlet 10. In addition, when a series of the above-described work for printing is finished, the leading edge of the paper 1 is returned to the print stand-by position PS in FIG. 7.
In the sublimation type color printer, when dust and the like lie on the paper, or the paper is folded, inks are not transferred on this part and an insufficient transfer occurs. Such an insufficient transfer reduces the commercial value of the output device for the digital camera in which a high-quality picture is required.
Furthermore, in addition to the quality requirements of the picture, the reduction of the running cost is also required for the widespread adoption of the pictures by the sublimation type color printer instead of photographs using silver-salt.
However, in the conventional sublimation type color printer as described above, the paper 1 at the print stand-by position PS is prepared away from the roll 2, and therefore, dust can easily accumulate on the paper 1. Furthermore, the paper 1 at the print stand-by position PS is prepared in a holding manner by the guides 7 and the first transfer rollers 4 which locate the upper and lower sides of the paper 1, and therefore, the paper 1 can easily become folded.
In addition, the dust which attaches to the paper 1 at the production of the paper 1, the dust which exist in the printer and lies on the surface of the paper 1, and cellulose which exist in the paper 1 and lies on the surface of the paper 1, are thought to be the source of the dust which causes the insufficient transfer However, it is difficult to remove this dust completely.
The present invention is provided in consideration of the above circumstances, and purposes of the present invention are to provide a sublimation type color printer which can provide a high-quality picture with low running cost.